Weird studder when floor the peddle: pls help

ther1pper · 06-17-2005

hey.. i have a 98 gsx, and like i got this car and like i was driving it, and like it started to studder alot when i press the gas hard, it like jerks alot like its not getting gas to the engine or some shit, i have had like 4 or 5 people ride with me to try and figure it out, someone said it might have something to do with the injection system, but im not sure, anyone had a idea???? if u know what im talking about?? pls help

**Halon** · 06-17-2005

How violent is this jerking? Are you running stock boost? It could be fuel cut, meaning you're running too much boost, not enough fuel, and your car kinda shuts down for a second, then kicking back in, causing a rather violent jerk. To correct that you'll need a better fuel pump.

**Kracka** · 06-17-2005

Like, check like your like plugs and probably like your plug wires too. More than likely, you need new ones of both.

**Kracka** · 06-17-2005

Quote:

Originally Posted by me612

How violent is this jerking? Are you running stock boost? It could be fuel cut, meaning you're running too much boost, not enough fuel, and your car kinda shuts down for a second, then kicking back in, causing a rather violent jerk. To correct that you'll need a better fuel pump.

How exactly is just a fuel pump going to eliminate fuel cut?

ther1pper · 06-17-2005

the car never turns off tho, it jsut like jerks violently, i dont know, someone said it might be the fuel pump, but im running 9psi right now.. im not sure what stock is but yea.. anything?

EclipseGST · 06-17-2005

Try a Boost leak test. Seems as if you are getting fuel cut but yet arent seeing the air flow that would create it.

Go to www.vfaq.com and make yourself a boost leak tester and search for leaks. If you dont find any then go on to the next possible cause. Spark plugs/wires like was mentioned before! Good luck.

Quote:

Originally Posted by S2kracka

Like, check like your like plugs and probably like your plug wires too. More than likely, you need new ones of both.

LMAO... That was well put!

EclipseGST · 06-17-2005

Quote:

Originally Posted by me612

How violent is this jerking? Are you running stock boost? It could be fuel cut, meaning you're running too much boost, not enough fuel, and your car kinda shuts down for a second, then kicking back in, causing a rather violent jerk. To correct that you'll need a better fuel pump.

A fuel pump will not eliminate fuel cut. Fuel cut happens when the computer sees too much air flow (from the mass air sensor located before the turbo) for the stock fuel system to keep up with so it cuts spark and fuel delivery to the motor. The only way around it (with a bigger turbo running more boost) is with either a computer chip, fuel controller or some sort of engine management. It would be pointless to do this on a stock fuel setup so there for you would want to upgrade your injectors and fuel pump while your at it.

You should not have fuel cut on the stock turbo at this time of the year running 9psi. There for it leads me to believe you have a boost leak but the turbo is still trying to boost the same amount of pressure into the intake. While trying to do that the air is just leaking out so the turbo is pulling in more air to make up for the loss. This is why you are only seeing 9psi.

LightningGSX · 06-17-2005

Check the TPS.When the TPS is not functioning properly, you won't get accell enrichment, which pretty much sounds like your problem

EDIT: Definately start with new plugs and wires though.

**Halon** · 06-17-2005

Quote:

Originally Posted by EclipseGST

A fuel pump will not eliminate fuel cut. Fuel cut happens when the computer sees too much air flow (from the mass air sensor located before the turbo) for the stock fuel system to keep up with so it cuts spark and fuel delivery to the motor. The only way around it (with a bigger turbo running more boost) is with either a computer chip, fuel controller or some sort of engine management. It would be pointless to do this on a stock fuel setup so there for you would want to upgrade your injectors and fuel pump while your at it.

You should not have fuel cut on the stock turbo at this time of the year running 9psi. There for it leads me to believe you have a boost leak but the turbo is still trying to boost the same amount of pressure into the intake. While trying to do that the air is just leaking out so the turbo is pulling in more air to make up for the loss. This is why you are only seeing 9psi.

deng, well I stand corrected. I had always understood that fuel cut was when your computer sees that you are running too lean, which in a lot of cases was usually caused by people pushing their little stock fuel pumps past it's limits. So by getting a larger pump, it usually helped in eliminating that. Guess I understood wrong, my bad. Sorry for the bad info.

ther1pper · 06-17-2005

ight thanks for the help... imma go get some new plugs and new wires and see how that works out.. ill report back eventually

INTRIGUED · 06-17-2005

werd homie

ther1pper · 06-19-2005

hey just reporting back, ight so i went and got new plugs and new wires.. put them in.. went for a test drive and it fixed my problem... thanks for the advice guys